Studies on the performance of migratory corrosion inhibitors in protection of rebar concrete in Gulf seawater environment

Abstract

In recent years, migratory corrosion inhibitors (MCI) have been suggested as the possible chemicals for rehabilitating the damaged reinforced concrete structure. The inhibitor migrates through the concrete to the reinforcing steel and protects it from further corrosion by providing a thin, protective coating of MCI-molecules on steel reinforcement. Studies have been carried out to investigate the performance of dimethyl ethanol amine based MCI-A and triethanol amine based MCI-B as surface coatings. Reinforced concrete specimens coated with MCI-A and MCI-B were subjected to exposure tests in salt solutions. The tests were consisted of immersing the specimens in 5% NaCl solutions (laboratory tests) and open seawater or exposing the specimens to high tide (splash zone) for periods ranging from 6 to 12 months. The condition of the exposed specimens was evaluated by physical examination of the rebar and also by carrying out electrochemical measurements. The electrochemical studies were consisted of open circuit potential and polarization measurements. The experimental data from the studies have been analyzed and the usefulness of MCI in protecting the rebar concrete is discussed.